Whether the bathroom is built with a wall or a ventilation duct first

Ventilation ducts cannot be removed without permission, although they are indoors, but they are the common part of the building. There are also clear provisions in the relevant building decoration regulations of the state, which is a prohibited renovation behavior.

Can be used separately. That is: either make holes in the walls of the kitchen room so that the pipes between the kitchens lead directly to the outside; Either make holes in the walls of the bathroom and open the ventilation ducts of the bathroom to the outside.

It's possible.

It is recommended to find a board with a similar color (such as aluminum-plastic panel, paint-free board, etc.), dig a hole according to the diameter of the air duct, glue the board to the wall, and then glue the pipe. >>>More

It is connected from low to top, all the way to the roof.

Blocked the same infiltration, the 2nd floor has infiltration, if there is a high place, or not close to the water pipe, there is also a place that is above the 3rd floor, if there is no infiltration on the 3rd floor, it should be the 3rd floor leakage (water flows down), if it is a slow leakage, the leak is not felt, only he can be soaked below.